Comet 3I/ATLAS, the third known visitor from beyond our Solar System, has been brightening rapidly as it approaches perihelion.
Due to its position behind the Sun, ground-based observations were nearly impossible, so astronomers used space-based observatories and solar-monitoring satellites.
Researchers Qicheng Zhang and Karl Battams captured the comet's transformation using these instruments.
Related: Strange Green Glow From Interstellar Comet 3I/ATLAS Has Scientists Puzzled
Astronomers are surprised by the comet's blue shine.
Author's summary: Comet 3I/ATLAS surprises astronomers.